1. Field of the Invention
The present invention relates generally to implantable medical devices, and more particularly to an improved operating system architecture incorporating a piezoelectric layer-wise pump and valve for use in local administration of biological response modifiers and chemotherapeutic agents in tumor fighting.
2. Description of the Related Art
The underlying hypothesis of using cytotoxic drug is that more is better. Thus, a first step in administrating a cytotoxic agent is to determine the maximum tolerated dose (MTD). However, when used in traditional treatment modes, such as chemotherapy, the cytotoxic agents are delivered to the patient in a manner that allows the cytotoxic agents to be distributed more or less globally throughout the body of the patient. Relatively large doses of the drugs are required since only a small fraction of the administered dose will be present at the tumor site at any given time. The remainder of the dose will be in other parts of the body. Moreover, a major problem with conventional chemotherapy is the lack of specificity of the cancer cell.
The use of large doses of toxic agents often leads to serious and debilitating side effects. Moreover, the global administration of drugs is often not compatible with combination therapies where a number of medicating agents are used synergistically to treat tumors or other conditions. Thus, the global administration of medicating agents to treat tumors and other such medical conditions is an inefficient, often dangerous, technique that often leads to severe or debilitating side effects.